Search

Biogenic volatile organic compounds (BVOCs) emitted by tropical plants represent a significant proportion of global emissions, but the in-situ BVOC measurements in tropical rainforests are extremely sparse. Herein, a vehicle-mounted mobile monitoring system was developed for in-situ online investigations of BVOC emissions from thirty representative tree species in the tropical rainforests of Hainan Island, southern China. The results showed that monoterpenes were the primary BVOCs emitted from most broadleaf trees. Isoprene, sabinene, γ-terpinene and β-ocimene were the most abundant BVOCs. Localized canopy-scale emission factors (EFs) exhibited notable discrepancies with the defaults in the Model of Emissions of Gases and Aerosols from Nature (MEGAN), specifically with isoprene EFs being slightly lower than the model, while the EFs for monoterpenes and sesquiterpenes were 1 to 27 times higher than those in MEGAN. The BVOC emission inventory for the predominant mature forest species in Hainan Island in 2023 was further estimated to be 244.43 Gg C·yr -1 , with isoprene and monoterpenes accounting for 74 % and 16 %, respectively. Additionally, unimodal monthly variation patterns were revealed, with BVOC emissions peaked in July (30.08 Gg C·yr -1 ) and bottomed in January (8.84 Gg C·yr -1 ). This study demonstrates the potential and versatility of the applied mobile platform for in-situ online measurements of plant volatiles. Our findings provide important data support for reducing uncertainties in BVOC emission estimations in tropical rainforests and for evaluating their health benefits in the context of forest therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Two acylhydrazone based zinc(II) complexes [Zn(HL) 2 Cl 2 (CH 3 OH) 2 ] (Zn1) and [ZnL(AC)] 2 (Zn2) were synthesized from 3-(1-(salicyloylhydrazono)ethyl) pyridine (HL). Single crystal X-ray structure analyses showed that complexes Zn1 and Zn2 have a zero-dimensional monomer or dimer structure. Antiproliferative activity studies revealed that Zn1 and Zn2 are both more effective against A549 cells than cisplatin. The results of the reactive oxygen species (ROS) generation assay on A549 cells showed that both Zn1 and Zn2 induced apoptosis through ROS accumulation. The apoptosis-inducing and cell cycle arrest effects of Zn1 and Zn2 on A549 cells indicated that the antitumor effect was achieved through apoptosis induction and inhibition of DNA synthesis by blocking the G 0 /G1 phase of the cell cycle. What's more, the results of wound-healing assay showed that Zn1 and Zn2 could inhibit the migration of A549 cells. Western blot analysis further demonstrated that Zn1 and Zn2 induced cell apoptosis through the mitochondrial pathway, in which process, the expression level of cytochrome C, cleaved-PARP, cleaved-caspase 3 and cleaved-caspase 9 proteins increased while pro-caspase 3 and pro-caspase 9 expression decreased. In vivo anticancer evaluation demonstrated that both Zn1 and Zn2 complexes effectively inhibited tumor growth without causing significant toxicity in systemic organs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Competing Interests: Competing interests: The BMJ has judged that there are no disqualifying financial ties to commercial companies. The authors declare the following other interests: none.

Background: During normal sinus rhythm, atrial depolarization is conducted from right atrium to left atrium through Bachmann's bundle, and a normal P wave axis which is measured on the frontal plane is between 0º and + 75º. The change of P wave polarity is helpful for the analysis of origin point., Case Presentation: We report a patient with negative P wave in lead I. The characteristics of QRS complex in leads V 1 to V 6 are helpful to preliminarily differential diagnosis. The 12-lead electrocardiogram (ECG) with correct limb leads (right arm-left arm) placement shows sinus rhythm with complete right bundle branch block (RBBB)., Conclusions: The change of P wave polarity as well as characteristics of QRS complex can help identify limb-lead reversals., (© 2024. The Author(s).)

Competing Interests: Competing interests: The BMJ has judged that there are no disqualifying financial ties to commercial companies. The authors declare the following other interests: none. Further details of The BMJ policy on financial interests are here: https://www.bmj.com/about-bmj/resources-authors/forms-policies-and-checklists/declaration-competing-interests

This paper uses ANSYS Workbench platform to simulate the casting and rolling composite process, taking the horizontal type casting and rolling machine as the research object, and conducts the numerical simulation study of copper-aluminum composite solid-liquid casting and rolling heat-flow coupling, mainly to study different walking speed, aluminum pouring temperature, casting and rolling zone length, heat transfer coefficient on the temperature field, liquid phase rate influence law, and use it as a theoretical guide for copper-aluminum solid-liquid casting. The experiments of copper-aluminum solid-liquid casting-rolling composite were carried out to optimize the process parameters and to verify the experiments, so as to prepare a well-bonded copper-aluminum composite plate. The composite mechanism in the preparation of copper-aluminum composite plate was analyzed, and it was clarified that the interfacial layer was formed through four stages: contact between copper and aluminum surfaces, contact surface activation, mutual diffusion of copper and aluminum atoms, and reaction diffusion.

Three metal complexes [CuL(NO 3 )] n (1), [Cd(HL)(NO 3 ) 2 ] n (2) and [EuL(HCOOH)(H 2 O)(NO 3 ) 2 ] (3) were synthesized with a pyridyl Schiff ligand L ( N '-[(1 E )-pyridin-2-ylmethylidene]pyridine-4-carbohydrazide). A crystallographic study revealed that complexes 1 and 2 have a chain structure, and complex 3 is a zero-dimensional monomer. In vitro cytotoxicity studies showed that complex 2 had the best antiproliferative activity against SMMC-7721 cells and complex 3 had the best antiproliferative activity against MDA-MB-231 cells with single-digit IC 50 values, both exceeding those of the control drug cisplatin by far. The cell invasion and migration ability through the transwell assay and wound-healing assay showed that the selected complexes could inhibit the invasion and migration of cancer cells. The Hoechst staining assay and ROS generation assay with SMMC-7721 cells indicated that the cytotoxic effects of complex 2 involved apoptosis induction through ROS accumulation. The apoptosis-inducing and cell cycle arrest effects of complex 2 on SMMC-7721 cells indicated that the antitumor effect was achieved through apoptosis induction and inhibition of DNA synthesis by blocking the G 0 /G 1 phase of the cell cycle. In addition, complex 2 showed significant inhibition against B. dysentery with an inhibition circle diameter of 24 mm.

Objective: To formulate the classification criteria of femoral intertrochanteric fractures based on irreducibility or not in order to predict the difficulty of fracture recovery., Methods: A clinical data of 244 patients with closed femoral intertrochanteric fractures admitted between January 2017 and March 2020 was retrospectively analyzed. There were 116 males and 128 females with an average age of 77.9 years (range, 45-100 years). The cause of injury included falling in 190 cases, traffic accident in 36 cases, smashing in 13 cases, and falling from height in 5 cases. The time from injury to operation was 1-14 days (mean, 3.6 days). According toAO/Orthopaedic Trauma Association (AO/OTA) classification, the fractures were classified as type 31-A1 in 38 cases, type 31-A2 in 160 cases, and type 31-A3 in 46 cases. According to whether the recovery difficulty occurred after intraoperative closed traction reset, the patients were divided into reducible-group and irreducible-group; combined with the literature and preoperative imaging data of two groups, the classification criteria of femoral intertrochanteric fractures was formulated based on the irreducibility or not. The 244 fractures were classified by the doctors who did not attend the operation according to the classification criteria, predicted the difficulty of fracture reduction, and compared with the actual intraoperative reduction situation., Results: The 244 patients were divided into reducible-group ( n =164, 67.21%) and irreducible-group ( n =80, 32.79%) according to the intraoperative difficulty of reduction. Comparing the imaging data and characteristics of the two groups, and formulating the classification criteria of femoral intertrochanteric fractures based on irreducibility or not, the fractures were mainly divided into two categories of irreducibility and reducibility. The fractures of irreducibility category was divided into typesⅠ-Ⅴ, among which type Ⅲ was divided into subtypes 1-4; the fractures of reducibility category was divided into typesⅠand Ⅱ. Compared with the actual intraoperative evaluation results, the total accuracy rate of the doctors who did not attend the operation was 81.15% (198/244) based on the classification criteria of femoral intertrochanteric fractures. The accuracy rate of irreducibility category was 65.74% (71/108), and the reducibility category was 93.38% (127/136). All patients were followed up 13-25 months, with an average of 17.6 months. All fractures healed except 2 cases died of infection., Conclusion: The classification criteria of femoral intertrochanteric fractures based on irreducibility or not can accurately predict the reducible cases preoperatively, and most of the irreducible cases can be correctly predicted in a wider way. But the classification criteria still need to be further improved and supplemented.

Chrysomya bezziana is an obligate, myiasis-causing fly in humans and warm-blooded animals throughout the tropical and subtropical Old World. We report a case of cutaneous myiasis due to C. bezziana in a dog from Guangxi province in China. A total of 35 maggots were removed from the lesions. Direct sequencing of the mitochondrial cytochrome b gene showed that the specimen belonged to haplotype CB_bezz02, which was previously reported in Malaysia and the Gulf region. This paper also reviews reported cases of screwworm myiasis from humans and animals in China. Geographical records indicate that the distribution of C. bezziana is expanding, suggesting that an integrated pest management control should be taken into consideration in China.

Background: Preexcitation syndrome is characterized by a dominant delta wave on the baseline electrocardiogram (ECG), resulting from the change in QRS initial vector by the accessory pathway (AP). This study is to explore the effect of ventricular preexcitation on the QRS initial, maximal and terminal vector in an experimental rabbit with preexcitation syndrome induced by programmed electrical stimulation., Methods: Rabbits (n = 10) were randomized for the experimental model of ventricular preexcitation. Sensing and stimulating electrode catheters were placed in the high right atrium and along epicardial surface of atrioventricular groove of the left ventricular anterior wall, respectively. Programmed premature stimulation S 2 was synchronized with P wave and utilized to stimulate the ventricle. The ECG recorded the electrical activity of the heart. As compared with the QRS complex during sinus rhythm, paced QRS was assessed regarding the initial, maximal and terminal vector. PS 2 interval and PR interval were also measured and analyzed., Results: Preexcitation was successfully simulated by ventricular pacing in the rabbits, including (1) Complete preexcitation: PS 2 interval was less than PR interval; the difference was more than or equal to 47.00 ± 7.53 ms. (2) Incomplete preexcitation: PS 2 interval was less than PR interval; the difference was less than 47.00 ± 7.53 ms. (3) Incomplete latent preexcitation: PS 2 interval was more than or equal to PR interval; the difference was less than or equal to 13.00 ± 3.50 ms. (4) Complete latent preexcitation: PS 2 interval was more than or equal to PR interval; the difference was more than 13.00 ± 3.50 ms., Conclusions: The difference in the relative conduction velocity of the atrioventricular node versus the AP pathways determines the degree of preexcitation and different manifestation on ECG. The QRS terminal vector also reflects the ventricle preexcitation, indicating a valuable sign for the diagnosis of atypical or latent preexcitation.

This study is to investigate the effects of slow breathing on heart rate variability (HRV) and arterial baroreflex sensitivity in essential hypertension.We studied 60 patients with essential hypertension and 60 healthy controls. All subjects underwent controlled breathing at 8 and 16 breaths per minute. Electrocardiogram, respiratory, and blood pressure signals were recorded simultaneously. We studied effects of slow breathing on heart rate, blood pressure and respiratory peak, high-frequency (HF) power, low-frequency (LF) power, and LF/HF ratio of HRV with traditional and corrected spectral analysis. Besides, we tested whether slow breathing was capable of modifying baroreflex sensitivity in hypertensive subjects.Slow breathing, compared with 16 breaths per minute, decreased the heart rate and blood pressure (all P < .05), and shifted respiratory peak toward left (P < .05). Compared to 16 breaths/minute, traditional spectral analysis showed increased LF power and LF/HF ratio, decreased HF power of HRV at 8 breaths per minute (P < .05). As breathing rate decreased, corrected spectral analysis showed increased HF power, decreased LF power, LF/HF ratio of HRV (P < .05). Compared to controls, resting baroreflex sensitivity decreased in hypertensive subjects. Slow breathing increased baroreflex sensitivity in hypertensive subjects (from 59.48 ± 6.39 to 78.93 ± 5.04 ms/mm Hg, P < .05) and controls (from 88.49 ± 6.01 to 112.91 ± 7.29 ms/mm Hg, P < .05).Slow breathing can increase HF power and decrease LF power and LF/HF ratio in essential hypertension. Besides, slow breathing increased baroreflex sensitivity in hypertensive subjects. These demonstrate slow breathing is indeed capable of shifting sympatho-vagal balance toward vagal activities and increasing baroreflex sensitivity, suggesting a safe, therapeutic approach for essential hypertension.

Objective: The P-QRS-T wave on surface electrocardiogram (ECG) reflects the changes in atrial and ventricular electrical properties. However, the atrioventricular conduction system potentials cannot be recorded to date. This study aimed to explore the possibility of micropotential of the atrioventricular conduction system recorded by surface "SAN-Atrial-AVN-His (Saah) ECG.", Methods: We randomized 100 healthy volunteers (50 females and 50 males; mean age 25.12±1.62 years) to receive "conventional 12-lead ECG" and "Saah ECG," which were recorded by the "Saah ECG" machine. We recorded and further analyzed "conventional 12-lead ECG" and "Saah ECG." According to the microwavelets before the QRS complex, the PR interval was the sum of three intervals: PAs interval (PA interval recorded on surface ECG), AHs interval (AH interval recorded on surface ECG), and HVs interval (HV interval recorded on surface ECG). The PR interval, PAs interval, AHs interval, and HVs interval were measured., Results: Not only the P-QRS-T waves but also the microwavelets before the P wave, before the QRS complex, and after the QRS complex were recorded in 100 healthy volunteers. The PAs interval, AHs interval, and HVs interval were 22-37 (31.23±2.93) ms, 60-103 (76.07±13.43) ms, and 39-55 (49.29±4.44) ms, respectively. The PAs interval, AHs interval, and HVs interval were consistent with the intracardiac measurements (PA, AH, and HV intervals) obtained in previous studies. Compared with female volunteers, male volunteers had a longer AHs interval (p<0.05)., Conclusion: Not only the P-QRS-T waves but also the microwavelets before the P wave, before the QRS complex, and after the QRS complex were recorded on surface ECG. The wavelets before the QRS complex may be related to atrioventricular nodal, His bundle (bundle branch) potentials.

Background: The micro waveform of His bundle potential can't be recorded beat-to-beat on surface electrocardiogram yet. We have found that the micro-wavelets before QRS complex may be related to atrioventricular conduction system potentials. This study is to explore the possibility of His bundle potential can be noninvasively recorded on surface electrocardiogram., Methods: We randomized 65 patients undergoing radiofrequency catheter ablation of paroxysmal superventricular tachycardia (exclude overt Wolff-Parkinson-White syndrome) to receive "conventional electrocardiogram" and "new electrocardiogram" before the procedure. His bundle electrogram was collected during the procedure. Comparative analysis of PA s (PA interval recorded on surface electrocardiogram), AH s (AH interval recorded on surface electrocardiogram) and HV s (HV interval recorded on surface electrocardiogram) interval recorded on surface "new electrocardiogram" and PA, AH, HV interval recorded on His bundle electrogram was investigated., Results: There was no difference (P > 0.05) between groups in HV s interval (49.63 ± 6.19 ms) and HV interval (49.35 ± 6.49 ms). Results of correlational analysis found that HV S interval was significantly positively associated with HV interval (r = 0.929; P < 0.01)., Conclusions: His bundle potentials can be noninvasively recorded on surface electrocardiogram. Noninvasive His bundle potential tracing might represent a new method for locating the site of atrioventricular block and identifying the origin of a wide QRS complex.

In order to study the primary fragmentation behavior of coals and biomasses, experiments of rapid pyrolysis were carried out. This work focused on the devolatilization and fragmentation characteristics including the solid/gas yield, particle density/morphology, particle size and fragmental probability (S f ). The effects of temperature, time and solid property were investigated. The viscous flow model was employed to characterize the pressure difference (ΔP), which was considered as the driving force of diffusion and fragmentation. The Ohm principle was used to establish the linear relation of devolatilization rate and fragmentation rate. The result showed that temperature and time have positive contribution to the fragmentation. The occurrence of fragmentation was observed more apparently with the decreasing of the ash content in the biomass. The pressure difference has a positive correlation with the fragmental rate, which shows the validity of application Ohm principle in the prediction of fragmenting process., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Preexcitation syndrome could affect terminal QRS vector, which is not emphasized in clinic. In this study, we made a comparison between vectorcardiogram (VCG) before and after ablation to observe the change of terminal QRS vector. Furthermore, the relationship between the change of terminal QRS vector and accessory pathway (AP) as well as the change of initial QRS vector (delta vector) was analyzed., Methods: Thirty patients who were proved to have a single AP by ablation were included. All patients were divided into seven groups based on the AP location. Comparison between VCG before and after ablation was made to observe the change of terminal and delta vector. The relationship between the change of terminal QRS vector and AP location as well as delta vector was analyzed., Results: (1) All 30 patients had a change in terminal QRS vector (elevation and/or azimuth) in comparison to postablation VCG. (2) The change of terminal QRS vector was related to delta vector and AP location. The agreement and consistency between the change of terminal QRS vector and delta vector were 91.65% and 0.856 (P < 0.01), respectively., Conclusions: (1) Both initial and terminal QRS vector are affected by the antegrade conduction of AP. The change of terminal QRS vector is related to the AP location and delta vector. (2) The effect of preexcitation syndrome on QRS terminal vector is shown as more intuitive and easy in spatial vector by comparison with electrocardiogram, which is helpful for the diagnosis of atypical preexcitation and localization of AP., (© 2016 Wiley Periodicals, Inc.)

Aim: The objective of our study was to assess diagnostic value of three-dimensional (3D) vectorcardiographic (VCG) parameters in detecting pulmonary arterial hypertension (PAH) in chronic obstructive lung disease (COLD) with and without right ventricular hypertrophy (RVH)., Methods: The study group of 62 patients with COPD was stratified on the basis of color Doppler echocardiographic findings into three subgroups: non-PAH (n = 23), PAH without RVH (n = 22), and PAH with RVH (n = 17). Pairwise differences between the subgroups were evaluated by one-way analysis of variance, and Pearson correlation analysis was used to evaluate the significance of the correlations between pulmonary arterial systolic pressure (PASP) and various VCG parameters., Results: The azimuth of the QRS vector decreased from -24° in the non-PAH group to -62° in PAH without RVH and to -140° in PAH with RVH (P < 0.01 for pairwise differences between all three groups). Similar significant decrease was observed for the azimuth of the ventricular gradient (VG) vector. Spatial QRS/T angle increased from 69° in the non-PAH group to 115° in PAH without RVH (P < 0.01). In the PAH group with RVH, QRS/T angle was 94° (P < 0.05 for difference from the non-PAH group). There was a significant correlation between PASP and QRS/T angle (r = 0.89, P < 0.05) and between PASP and the azimuth of the VG vector (r = 0.86, P < 0.05). PASP increase from linear regression model was 0.8 mmHg for a QRS/T angle increase by 10° and 1.3 mmHg for each 10° increase in the azimuth of the VG vector., Conclusion: 3DVCG parameters are potentially useful for predicting PASP in COLD patients, and possibly also for differentiation between COLD patients with PAH and RVH from those without RVH., (© 2015 Wiley Periodicals, Inc.)

In our study, not only the P-QRS-T waves but also the micro-wavelets before QRS complex (in P wave and PR segment) and after QRS complex (ST segment and upstroke of T wave) were first to be identified on surface electrocardiogram in human by the "new electrocardiogram" machine (model PHS-A10) according to conventional 12-lead electrocardiogram connection methods. By comparison to the conventional electrocardiogram in 100 cases of healthy individuals and several patients with arrhythmias, we have found that the wavelets before P wave theoretically reflected electrical activity of sinus node and the micro-wavelets before QRS complex may be related to atrioventricular conduction system (atrioventricular node, His bundle and bundle branch) potentials. Noninvasive atrioventricular node and His bundle potential tracing will contribute to differentiation of the origin of wide QRS and the location of the atrioventricular block. We also have found that the wavelets after QRS complex may be associated with phase 2 and 3 repolarization of ventricular action potential, which will further reveal ventricular repolarization changes., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The preexcitation syndrome may either simulate myocardial infarction (MI) or mask it. The rapid anterograde conduction through accessory pathway may obscure atrioventricular (AV) block of the normal AV-nodal tract. To our knowledge, the case of various degree AV-nodal and bypass tract block after MI in a patient with preexcitation syndrome has been infrequently reported. We report a complex case of preexcitation syndrome presenting with first-degree and transient third-degree AV blocks in both normal and accessory pathways after acute MI. Subsequently, we further discuss the diagnosis of MI in preexcitation syndrome and analyze the electrocardiographic character of AV block in preexcitation syndrome.

The Brugada syndrome is a genetic disease (mutation of the SCN5A gene) that predisposes to syncope and life-threatening sudden cardiac death. The case highlights the importance of recognizing hyperkalemia, as potential triggers of the acquired Brugada sign with electrical alternans., (©2012, Wiley Periodicals, Inc.)